Double cage heart valve



June 20, L. EDWARDS DOUBLE CAGE HEART VALVE Original Filed April 1, 1963IN VEN TOR llffarney United States Patent 3,325,827 DOUBLE CAGE HEARTVALVE Miles Lowell Edwards, Santa Ana, Califi, assignor to EdwardsLaboratories, Inc., Santa Ana, Calif, a corporation of CaliforniaOriginal application Apr. 1, 1963, Ser. No. 269,299, now Patent No.3,263,239, dated Aug. 2, 1966. Divided and this application Apr. 11,1966, Ser. No. 541,841

Claims. (Cl. 31)

This application is a division of co-pending application Ser. No.269,299 filed April 1, 1963, now Patent No. 3,263,239 which is in turn acontinuation-in-part of Ser. No. 49,044 filed Aug. 11, 1960, now PatentNo. 3,099,016.

This invention relates to an artificial valve as a prosthesis in a heartto take the place of a defective natural valve.

The valve illustrated in said prior Patent 3,099,016 is a mitral valve,although the general features of construction therein disclosed areapplicable to both mitral and aorta valves. The claims of said PatentNo. 3,263,239 are directed to certain modifications of structure inorder to adapt the general principles of Patent No. 3,099,016 forutilization in an aorta valve. The claims in the present application aredirected to features which are of advantage in any heart valve where anunusually large port opening is desired in the valve whereby the claimedstruc ture is not limited to aorta valves.

The objects of the invention are, therefore, to provide an improvedartificial heart valve and to provide an improved form of constructionfor heart valves having an unusually large port opening in relation tothe size of the movable valve member.

The present valve is generally similar to the mitral valve mentionedabove but incorporates certain special features to increase the size ofthe port opening relative .to the size of the valve body and tofacilitate attachment of the sewing ring to the heart tissue directly atthe entrance to the aorta. Other features and advantages will becomeapparent from the following detailed description of the preferredembodiment illustrated on the accompanying drawing. All variations andmodifications within the scope of the appended claims are included inthe invention.

In the drawing:

FIGURE 1 is a longitudinal sectional view of a valve embodying theprinciples of the invention;

FIGURE 2 is a top plan view of the valve in reduced scale with partsbroken away;

FIGURE 3 is a bottom plan view of the valve; and

FIGURE 4 is a section of a human heart, showing the present valveinstalled therein.

The valve comprises an integral body member made of a suitable materialwhich is compatible with the human body. Various types of non-toxicplastic may be used, such as Du Pont Lucite acrylic resin, Rohm & HaasPlexiglas acrylic plastic, and the like. Metal is preferable to plastic,however, the preferred material being an alloy known as Stellite whichis non-corrodible and inert to blood and living tissue. Stainless steelmay also be used.

The entire body 10 comprising a base or port ring portion 11 and a cageportion 12 is preferably made in one piece either as a molding or acasting. The base ring defines a valve port having an internal sphericalseat 13 corresponding to the curvature of silicone rubber ball 15. Inorder to provide as large a port as possible, the maximum inclination ofseat 13 from the vertical is 15 as indicated by the angle at 16. Inorder to prevent any possibility of the ball escaping through the port,special retention means may be provided. These comprise three inwardlyand downwardly directed stop fingers 3,325,827 Patented June 20, 196717. Preferably, these stops are disposed between the three legs of cage12. The stops may be omitted when the dimensions and angularrelationships are such as to prevent the ball from escaping through theport in use. The resilient ball is inserted in the cage by squeezing itbetween two of the cage legs.

The outside of base ring 11 forms an annular channel 20 having a nearlyhorizontal bottom wall 21 having a slight downward inclination and anupwardly inclined top wall 22. 'In the illustrated embodiment theinclination of wall 22 is approximately 45. A flexible sewing ring 25 ismounted and secured in channel 20.

Sewing ring 25 preferably comprises a piece of knitted Teflon clothhaving a mid-portion clamped in the channel 20 by a one-piece splitspreader ring 26 of suitable material such as Teflon plastic. Thespreader ring 26 is itself channel-shaped in cross section with anexternal shape corresponding generally to the shape of channel 20 andhaving an outwardly facing channel 27. The spreader ring is clampedagainst at least one thickness of the cloth by a winding 28 of Teflonthread which is wound under tension in channel 27. When the body member10 is made of metal, all the other parts should be non-metallic toprevent electrolysis.

The lower end portion 30 of the cloth is folded back on upper portion 32and stitched with Teflon thread 31 to a folded back upper end portion 33of the cloth as shown. This produces a bight portion at 35 whichencloses a resilient silicone rubber ring 36. The cloth is formed into asmooth frusto-conical shape by a pressing operation. This results in asleeve of inverted flaring skirt shape which makes an angle of about 22with the vertical as indicated by the angle 40. Rubber ring 36 serves asan extensile element to stiffen the free upper end of the skirt and holdit extended in circular configuration in plan view. The folded endportions at 30 and 33 abut each other to form a pad having a thicknessof at least three layers of cloth. This provides secure anchorage forthe sutures. Rubber ring 36 is not necessary in small sizes of the valveas then the cloth will hold itself in conical shape without a separateextensile element.

FIGURE 4 shows the manner of installing the valve in a human heart 45.The heart has a left atrium 46, a left ventricle 47, a right atrium 48and a right ventricle 49. A mitral valve 50 prevents reverse flow ofblood from left ventricle 47 back into left atrium 46 and a mitral valve51 prevents reverse flow from right ventricle 49 back into right atrium48. Blood flows from left ventricle 47 through an aorta valve into aorta56 from whence is is distributed into main arteries 57 and othersleading to different parts of the body. The aorta normally makes a sharpbend between the heart and the arteries 57, as shown.

The present valve is usually installed by making an incision 52 throughthe outside of this bend which provides access for surgical treatment ofthe natural aorta valve. The natural aorta valve parts are removed andthe present valve is installed in the same location. The sewing ring 25is secured to living tissue at the entrance to the aorta by threads orsutures 53 with the cage 12 extending up into the aorta. The suturing isfacilitated by the action of extensile rubber ring 36 which holds theupper free end of the skirt portion of the sewing ring expanded intocontact with the inside of the aorta wall, as shown. Normally, the aortaincreases in size at this point whereby the flare of the skirt of thesewing ring conforms generally with the taper of the aorta.

The combination of upwardly inclined wall 22, the top surface of whichconforms to the flow pattern of the blood, and the spacing of stopfingers 17 staggered between cage legs 12 provide maximum flow aroundthe legs 12. This minimizes the tendency toward a shadow in the flowpattern between the legs and the sewing ring where clots could form.Usually about two-thirds of the sutures may be tied against the innersurface of the conical sewing ring adjacent to the legs of the cage.These suture knots are inclined to excite the clot formation. Thestaggered arrangement of stop fingers and cage legs is to avoid aconcentration of impediments in the flow through the valve. Thisprovides maximum washing of blood around the cage legs to the areadirectly between the leg and the inside of the sewing skirt to minimizethe possibility of clot formation at that area.

It is to be noted that the valve is installed below the coronaryarteries 55 so that it functions in the circulatory system the same asthe natural aorta valve.

A'most important feature of the valve is the expansile sewing ringbrought about by the nature of the cloth used and the rubber ring placedin the upper extremity of the skirt. It aids the surgeon in selection ofa valve. Although measuring devices are used, they are not precise and acertain amount of flexibility here is important.

Another point is that the valve is installed when the aorta is at zeropressure. When in use, the pressure extends the aorta diameter and thesewing ring must expand accordingly.

There is also the important point that the rubber ring being placed atthe upper extremity of the skirt causes the pressure difference acrossthe valve, when the valve is in a closed position, to be sealed at thelocation of the rubber ring forcing the entire area of the skirt outwardagainst the aorta wall, preventing wrinkles. This action is very muchlike the seal in the leather cup of a bicycle tire pump.

Having now described my invention and in what manner the same may beused, what I claim as new and desire to protect by Letters Patent is:

1. A heart valve comprising a port ring, a movable valve membercooperating with the port in said ring, a cage for said valve membercomprising a plurality of spaced legs projecting upwardly and inwardlyfrom the upper side of said port ring, a plurality of stop fingers forsaid valve member projecting downwardly and inwardly from the lower sideof said port ring, and means for securing the valve to the tissue of aliving heart.

2. A heart valve as defined in claim '1, said securing means comprisinga suturing ring secured around the V periphery of said port ring.

3. A heart valve as defined in claim 2, said port ring having anoutwardly facing channel therearound and said suturing ring comprisingcloth, and a filamentary winding securing said cloth in said channel.

4. A heart valve as defined in claim 1, said fingers being staggeredbetween said legs.

5. A double cage heart valve prosthesis, said prosthesis having a ballarranged to cooperate with a port in a port ring wherein said port islarge enough to make it possible for the ball to pass therethrough, acage for said ball on the upper side of said port ring comprising aplurality of spaced legs projecting upwardly and inwardly from the upperside of said port ring, a second cage for said ball on the lower side ofsaid port ring comprising a plurality of stop fingers projectingdownwardly and inwardly from the lower side of the port ring, and meansfor securing the prosthesis to the tissue of a living heart.

References Cited UNITED STATES PATENTS 3,099,016 7/1963 Edwards 313,143,742 8/1964 Cromie 31 3,263,239 8/1966 Edwards et al 3-1 OTHERREFERENCES Development of a Titanium Double-Caged Full-Orifice BallValve, by Robert S. Cartwright et al., in Transactions American Societyfor Artificial Internal Organs, volume X, April .12, 1964, pages 231236.

RICHARD A. GAUDET, Primary Examiner.

ROBERT E. MORGAN, Examiner.

R. L. FRINKS, Assistant Examiner.

Disclaimer 3,325,827.M2'Zes Lowell Edwards, Santa Ana, Calif. DOUBLECAGE HEART VALVE. Patent dated June 20, 1967. Disclaimer filed J an. 2,1970, by the assignee, America n H ospital Supply Corporation. Herebydisclaims the terminal portion of the term of the said patent subsequentto August 2, 1983.

[Ofiicial Gazette April 14, 1.970.]

1. A HEART VALVE COMPRISING A PORT RING, A MOVABLE VALVE MEMBER COOPERATING WITH THE PORT IN SAID RING, A CAGE FOR SAID VALVE MEMBER COMPRISING A PLURALITY OF SPACED LEGS PROJECTING UPWARDLY AND INWARDLY FROM THE UPPER SIDE OF SAID PORT RING, A PLURALITY OF STOP FINGERS FOR SAID VALVE MEMBER PROJECTING DOWNWARDLY AND INWARDLY FROM THE LOWER SIDE OF SAID PORT RING, AND MEANS FOR SECURING THE VALVE TO THE TISSUE OF A LIVING HEART. 